Bosch 16861 Oxygen Sensor - Upstream

Bosch Actual OE Oxygen Sensor 16861

Bosch 16861 is an Actual OE Oxygen Sensor built as a narrow-band heated replacement for precise air-fuel-ratio feedback to the ECU. It supports stable combustion control and emissions management across changing engine loads, temperatures, and driving conditions.

This Bosch Actual OE Oxygen Sensor line draws on Bosch’s long OE development history, including early thimble-style sensors and later planar narrowband designs that improve light-off speed, lambda accuracy, and closed-loop response. For drivers servicing a Cadillac CTS, Cadillac STS, Cadillac SRX, Chevrolet Equinox, Pontiac Torrent, or Suzuki XL-7, Bosch 16861 provides an OE-style replacement built around the original application requirements.

Key Features

• Specific-fit narrow-band heated oxygen sensor
• 4-wire design with square connector and blade terminals
• Threaded mounting with 18 mm thread size and 22 mm hex
• Wiring harness included with 12.1 in harness length
• Metal housing and high-temperature-resistant construction
• Upstream application for listed vehicles
• Bosch part number 16861 for direct catalog lookup

Detailed Product Overview

Bosch 16861 uses advanced ceramic sensing elements and optimized heater control to deliver consistent signal output under thermal cycling and vibration. The narrow-band heated design helps the engine management system maintain accurate closed-loop operation, which is important when replacing a worn sensor that can affect fuel control and emissions performance. This Bosch Actual OE Oxygen Sensor is a direct replacement choice for 2008-2011 Cadillac CTS upstream, 2008-2011 Cadillac STS upstream, 2007-2009 Cadillac SRX upstream, 2008-2009 Chevrolet Equinox upstream, 2008-2009 Pontiac Torrent upstream, and 2007-2009 Suzuki XL-7 upstream. Cross-reference part numbers include 1821378J01 and 19353381 for the same application.

What It Helps Address

• Rich or lean fuel mixture readings caused by a failing upstream sensor
• Check engine light conditions related to oxygen sensor performance
• Reduced fuel control accuracy during closed-loop operation
• Emissions test failures tied to incorrect exhaust oxygen feedback
• Rough idle or drivability issues linked to slow sensor response

Installation Notes and Tips

Verify the connector shape, terminal count, thread size, and upstream location before installation. Bosch 16861 is a specific-fit sensor, so matching the vehicle year, make, model, and position is essential. Inspect the harness routing and connector condition during replacement, and confirm the exhaust bung threads are clean before threading in the new sensor.

Quality Assurance

Bosch backs this oxygen sensor with more than five decades of OE development experience. The design reflects Bosch’s focus on durable sensing elements, controlled heater performance, and OE-proven fitment standards used by vehicle manufacturers.